sbt
sbt Clean & assembly step sometime takes very long time
steps
sbt clean compile assembly takes very long time
problem
sometimes clean itself takes ~1218s but some times rungs very fast but the assembly step is always takes at least 45 mins to complete. i am using sbt 1.2.8 open jdk 8 with hotspot 64 bit in windows 10
the build.sbt has the below assemblyOption too
assemblyOption in assembly := (assemblyOption in assembly).value.copy(cacheOutput = false) ```
# content of sbtconfig.txt
```# Set the java args to high
-Xmx1G
-XX:MaxPermSize=512m
-XX:ReservedCodeCacheSize=512m
# Set the extra SBT options
-Dsbt.log.format=true
-Dsbt.task.timings=true
If this is mostly about sbt-assembly, let's move this to sbt/sbt-assembly.
It's very slow for me on the Windows drive in WSL2. A native checkout in WSL2 is very quick to assemble.
The problem is whenever a disk is involved, be it WSL1 or WSL2 or an old Hard drive with a spinning motor, the performance of the assembly is very much affected, due to its IO-Heavy strategy of unzipping files to disk. The problem is least-noticeable when I run the asembly on an SSD drive or even a Gen 4 NVME drive.
To put it in perspective, assembling the same project after a clean: WSL1 in the office using an SSD: anywhere from 10 to 30 minutes! NVME gen 4 drive (7000MB read/write) at home, using WSL2: 21 seconds!
I don't have the in-between numbers, i.e. native SSD, native spinning drive, WSL spinning drive, network drive, etc.
To cater for the general usage we should definitely refactor the assembly.
I am looking into this issue. My goal is to minimize disk usage as much as possible and rely more on in-memory buffering.
EDIT: For context, the assembly JAR size is around 80MB
I have been using v0.15.0 on a bunch of projects. recently had a project where I cleared the cache and then it would try to build for 20 minutes+ which was much longer than our usual assembly time (7-10 minutes). It got to the point where my Macbook pro would grind to a halt. Saw this issue and upgrade to 2.0.0-RC1 the project that wouldn't build was built from clean in about a minute with subsequent builds in ~30s. Ran it and everything appears in worked order so these updates definitely resolved a related issue I was having and overall is a dramatic improvement for our projects
+1 on latest build for those that are having slowdown with sbt clean assembly, version 1.X.X was taking 9 minutes. Bumped to 2.1.5, build finished in 21 seconds - incredible!
